This invention relates to a method of manufacturing paneling, siding and the like and more particularly to such method of manufacturing involving an improved method of controlling the thickness or weight of coatings applied in the manufacturing processes.
Hardwood and softwood plywood paneling and printed and painted particleboard have many uses in the construction trade. Some typical uses include household wall paneling, kitchen cabinets and desk and table tops. In addition to wood cabinets, there has been a growing trend in recent years to the manufacturing of vinyl-clad kitchen cabinets.
In the manufacture of traditional hardwood and softwood paneling and vinyl-laminated particleboards, various coatings are applied to the surface of the wood to condition the wood and prepare it for subsequent processing steps. For example, a water-based filler coating is first spread evenly over the surface of a substrate in the manufacture of printed paneling. The filler is forced into the pores in the surface of the wood mechanically and conditions the wood for the application of the base coating. In addition, a wet basecoat is later uniformly spread over the substrate. The basecoat serves as a base color for the wood substrate over which multi-head printing and/or embossing processes are used to achieve the desired color and aesthetic effect.
In the case of vinyl-laminated particleboard, an adhesive coating is applied to the wood substrate before lamination of the vinyl film onto the panel. It is important to control the exact amount of adhesive spread over the wood substrate to provide an adequate bond between the substrate and the vinyl. If an insufficient amount of adhesive is applied to the substrate, the vinyl will be easily stripped from its supporting surface and, in the more serious cases, may peel from the wood substrate.
One of the problems associated with the application of the coating materials has been the absence of an effective way to control the thickness or weight of the coating applied to the substrate. Control over the coating's thickness or weight is important to ensure a high quality product while at the same time keeping the coat of the coating material as low as possible. At the present time, the thickness or weight of the coating is roughly controlled by counting the panels that are coated for each gallon of coating material used to provide an indication of the average coating thickness or weight and making adjustments in the rate the coating material is applied in accordance with this measurement. This technique, however, fails to provide an accurate up-to-the-minute indication of each applied coating as the coating is being applied and, as a result, only a very rough control of the coating thickness is achieved.